1. Field of the Invention
The present invention relates to a display device and a method of fabricating a display device, and more particularly, to a liquid crystal display device having a high aperture ratio and a high brightness, and a method of fabricating the same.
2. Discussion of the Related Art
In general, a transflective liquid crystal display (LCD) device can be switched from a transmissive mode using transmission of light to a reflective mode using reflection of light according to the user's selection. Since the transflective LCD device uses light from a backlight unit and ambient artificial or natural light, the transflective LCD device is not restricted by environmental light and has advantages, such as low power consumption and high brightness.
FIG. 1 is an exploded perspective view of a transflective liquid crystal display device according to the related art. In FIG. 1, a transflective liquid crystal display (LCD) device 11 includes a first substrate 21 and a second substrate 15, and a liquid crystal layer 23 interposed therebetween. The first substrate 21 and the second substrate 15 are spaced apart from each other and include a plurality of pixel regions “P” having a transmissive portion “A” and a reflective portion “C.” A black matrix 16 and a color filter layer 17 including red, green and blue sub-color filters are formed on the second substrate 15. A common electrode 13 is formed on the black matrix 16 and the color filter layer 17.
A transparent pixel electrode 46 and a reflective electrode 40 are formed on the first substrate 21. The transparent pixel electrode 46 and the reflective electrode 40 correspond to the transmissive portion “A” and the reflective portion “C,” respectively. A gate line 25 formed on the first substrate 21 crosses a data line 27 to define the pixel region “P.” A thin film transistor (TFT) “T” of a switching element connected to the gate line 25 and the data line 27 is disposed in matrix.
The black matrix 16 corresponding to the gate line 25, the data line 27 and the TFT “T” is designed with an alignment margin. Alignment errors between the first substrate 21 and the second substrate 15 can be compensated within the alignment margin. Accordingly, the black matrix 16 is enlarged to accommodate the alignment margin.
FIG. 2 is a schematic cross-sectional view taken along a line “II-II” of FIG. 1 and FIG. 3 is a magnified cross-sectional view of a portion “E” of FIG. 2. In FIGS. 2 and 3, a thin film transistor (TFT) “T” including a gate electrode 8, an active layer 30, an ohmic contact layer 32, a source electrode 34 and a drain electrode 36 is formed on a first substrate 21. A first pixel region “P1” and a second pixel region “P2” both contain a transmissive portion “A” and a reflective portion “C.” A transparent pixel electrode 46 is formed to correspond to both the transmissive portion “A” and the reflective portion “C.” A reflective electrode 40 is formed in correspondence with the reflective portion “C.” A data line 27 is formed in a portion between the reflective portion “C” and the second pixel region “P2.” Although not shown in FIGS. 2 and 3, a gate line crosses the data line 27.
A color filter layer 17, including a red sub-color filter 17a, green sub-color filters 17b and a blue sub-color filter 17c, is formed in the pixel regions “P1 ” and “P2” on a second substrate 15 facing the first substrate 21. A black matrix 16 is formed to correspond to the data line 27. When a space between the adjacent reflective electrodes 40 over the data line 27 has a first distance “a” and a portion of the reflective electrodes 40 overlapping the data line 17 have a second distance “b,” the black matrix 16 has a width “a+2b.”
A uniform electric field is not sufficiently applied to a liquid crystal layer corresponding to the space between the adjacent reflective electrodes 40. Accordingly, the liquid crystal layer 23 (of FIG. 2) corresponding to the space between the adjacent reflective electrodes 40 has a light leakage even when a voltage corresponding to a black image is applied to the transparent pixel electrode 46 (of FIG. 2) in a normally white mode LCD device. Thus, the liquid crystal layer 23 (of FIG. 2) corresponding to the space between the adjacent reflective electrodes 40 would be shielded by the black matrix 16. Moreover, since the first substrate 21 and second substrate 15 can have an alignment error therebetween, the black matrix is designed to have the portion having the second distance “b” corresponding to the alignment margin. Accordingly, the black matrix 16 is enlarged and an effective area of the reflective portion “C” is reduced, thereby degrading aperture ratio and brightness.